1. Field of the Invention
The present invention relates generally to the construction industry and more particularly, to interlocking structural panels for use in building houses and other structures.
2. Description of the Prior Art
For many years, the desire for more economical housing has encouraged the development of a wide variety of structural building panels. An example are pre-assembled or pre-formed sandwich building panels, which are capable of fabrication off-site and then immediately being transferred to the building site, where they are easily and quickly erected at a minimum investment in cost and labor. The same kind of panels can also be fabricated at the building site.
Conventional building methods include the use of medium to high grade lumber materials usually employed on-site. These methods are demanding of much higher costs and substantially more labor, which translates into a finished structure that costs a great deal more money than one built using pre-formed panels.
A variety of problems are associated with the use of sandwich building panels in the prior art, including issues of overall structural integrity, component strength, compliance with rigid local building codes, economy of production and installation and building design compliance. Prior art building materials, such as lumber, depending upon how it is treated may also be extremely flammable. These earlier panels also suffer from the disadvantage of having to be constructed of different materials, the outer sheets or skin being made from one kind of material and the inner core being fabricated from another. This typically adds to the labor and cost of materials resulting in a more expensive end product.
Also, panels constructed of plywood or some other similar material are usually extremely heavy, which can create safety problems, and typically do not offer the kind of anti-shear resistance usually demanded by most, if not all, of the modern day building codes, especially those in earthquake zones and high wind environments.
Also inherent in the prior art are problems relating to the employment of wood forms to construct concrete walls for building a subterranean space, such as a basement. For example, in the prior art, a typical concrete form will utilize sheets of lumber, which have increased substantially in price over time, between which a concrete slurry is poured and eventually hardens. Conventional wire rods and rebar are usually employed to enhance the strength and integrity of the hardened concrete after the forms are removed. The problems involve the relatively high cost of the labor utilized to construct and later remove the forms. Another problem relates to the limited insulation offered by the concrete, which typically is exposed over its entire exterior surface to the surrounding soil and the moisture, heat and cold that penetrate through the soil.
The present invention is a vast improvement over the prior art panels and systems as it provides solutions to the problems described previously, including offering fireproof sandwich building panels that contain no wood, are easily fabricated and installed on-site and have a substantially higher level of structural integrity and strength. Each panel contains an inner core element, which is made of the same fireproof material as the outer panels. The core element includes a cooperating tongue and groove side design employed to resist anti-shear forces from all directions when a series of adjacent like panels are joined and bonded together. Shear forces are those forces which are directed at an object, in this instance an upstanding wall panel, from above, below or either side. Typically, this is the force that the walls of a building structure are least able to resist. A building that is able to resist shear loads by absorbing or transferring and distributing the loads among a series of panels is much more resistant to the kind of destruction usually caused by earthquakes and high winds.
The present invention also offers improvement over the prior art in the area of construction of subterranean spaces, such as a basement. The building panels and system, as described heretofore, may be employed to construct concrete forms, which are then left as a permanent part of the structure after the concrete cures. Using the same core element, alone or in combination with a prescribed amount of insulating material, these panels act initially as a concrete form and, thereafter, as a finished wall component for the basement interior and an effective insulator provided around the entire subterranean space. As they are not removed after the concrete hardens, there is an enormous savings in labor costs normally associated with the removal of the forms.